1. Field of the Invention
The present invention relates to a connector block which can be connected to an injector (a fuel injection valve) for use in an automobile.
2. Description of the Related Art
Now, FIG. 1 shows an example of the outer shape of a connector block 10 for an injector (which is hereinafter referred to as a connector block 10 simply). This connector block 10 is a device which is to be mounted into, for example, a V-type 6-cylinder engine (not shown); and, the connector block 10 comprises a housing 21 formed of heat resistant reinforced hard resin so as to have an elongated shape and also, conventionally, a group of bus bars 1 which are shown in FIG. 15.
By the way, referring to the structure of a V-type engine, a plurality of (for example, six) cylinders arranged along a crankshaft are inclined right and left every other cylinder to thereby provide a pair of cylinder groups and, as shown in FIG. 2, a plurality of injectors 51 (for example, by threes in each cylinder group) are projected obliquely upward from the two cylinder heads H, H of these right and left cylinder groups toward the centers of the two cylinder heads H, H. Here, in FIG. 2, of the two injector groups 50A, 50B respectively projected from the two cylinder heads H, H, there are shown two injectors 51, 51, that is, one injector in each injector group.
Now, the connector block 10, as shown in FIG. 2, includes, on the lower surface 21D of the housing, 21, a pair of injector connecting portion groups 25A, 25B to which the injector groups 50A, 50B can be respectively connected and, on the upper surface 21U of the housing 21, a wire connecting portion 22 to which an external wire 80, shown in FIG. 1. can be connected. And, the bus bar group 1 (see FIG. 15) extend over the individual injector connecting portions 25 of the respective injector connecting portion groups 25A, 25B as well as the wire connecting portion 22. Also, in the bus bar group 1, there are disposed a plurality of tabs 31 to be exposed in the respective injector connecting portions in such a manner that they are divided into a pair of tab groups 31A, 31B (see FIG. 15) respectively facing in obliquely downward directions which are different from each other.
By the way, as described above, since the bus bar group 1 includes the tab groups 31A, 31B which respectively face in the mutually different directions, to mold the housing 21, it is necessary to use a metal mold including such a slide mold 3 as shown in FIG. 17, or a metal mold including such a core 5 as shown in FIG. 18.
However, conventionally, for the following reason, there is no choice but to use a metal mold including a core 5 which is poor in operation efficiency. That is, in the conventional bus bar group 1, a grounding bus bar 8 shown in FIG. 16 is structured such that a pair of main body portions 8S, 8S thereof including a plurality of tabs 31 in correspondence to the respective injector connecting portion groups 25A, 25B are connected together through a horizontal branch portion 8H thereof; and, the grounding bus bar 8 and other power supply bus bars 9, as shown in FIG. 15, are unified by a holder 63 formed of synthetic resin, thereby forming one bus bar group 1. For this reason, as shown in FIG. 17, the two tab groups 31A, 31B differing in the facing direction are unified and thus cannot be inserted into a tab hold hole 4 formed in the slide mold 3, which makes it impossible to set the bus bar group 1 into the metal mold including the slide mold 3. By the way, even in case where the slide mold 3 is retreated once, the bus bar group 1 is set into the metal mold and, after then, the slide mold 3 is inserted again, because the leading end of the tab 31 is not positioned, the tab 31 cannot be inserted into the tab hold hole 4 of the slide mold 3, either.
Therefore, conventionally, as shown in FIG. 18, there is no choice but to use the metal mold including the core 5. Specifically, to mold the housing 21, there must be carried out the following extremely troublesome operations: that is, firstly, the core 5 is mounted on the bus bar group 1 (see FIG. 18); and, after then, the bus bar group 1 together with the core 5 is set into a metal mold main body 6, a product is taken out from the metal mold after the housing 21 is molded, and the core 5 is removed from the product.
The present invention aims at eliminating the drawbacks found in the above-mentioned conventional connector block for an injector. Accordingly, it is an object of the invention to provide a connector block for an injector which allows a bus bar group to be set in a metal mold including a slide mold and thus can be manufactured with high efficiency.
In attaining the above object, according to a first aspect of the invention, there is provided a connector block for an injector, comprising a housing molded by setting a bus bar group in a metal mold for resin molding, the housing including a wire connecting portion for connection with an external wire and a pair of injector connecting portion groups disposed in the lower surface of the housing for connection with a plurality of injectors from mutually different oblique downward directions, the bus bar group extending over the respective injector connecting portions and wire connecting portion, wherein the bus bar group is set in the metal mold while the bus bar group is divided into a pair of subordinate bus bar groups in correspondence to the pair of injector connecting portion groups, and the subordinate bus bar groups respectively include branched bus bars branched from the wire connecting portions and extending to the respective injector connecting portions, and also wherein the branched bus bars disposed in the two subordinate bus bar groups include a pair of short-circuit tabs to be conduction connected with each other by an external wire or by a short-circuit terminal.
Also, according to a second aspect of the invention, in a connector block for an injector as set forth in the first aspect of the invention, the housing further includes a recessed formed terminal storing recess, the pair of short-circuit tabs are erected from the bottom surface of the terminal storing recess, the short-circuit terminal for conduction connecting together the pair of short-circuit tabs is stored in the terminal storing recess, and only one of the pair of short-circuit tabs is connected to the external wire.
Further, according to a third aspect of the invention, in a connector block for an injector as set forth in the first or second aspect of the invention, the subordinate bus bar groups are respectively composed of a plurality of bus bars which are held together by a holder formed of synthetic resin.
According to the first aspect of the invention, by dividing the bus bar group into the pair of subordinate bus bar groups, the end portions of the bus bar group extending in mutually different directions in correspondence to the pair of injector connecting portion groups can be held separately in the metal mold. Thanks to this, the bus bar group can be set in the metal mold including a slide mold, which makes it possible to manufacture a connector block for an injector with high efficiency. Also, in the case of the branched bus bars of the respective subordinate bus bar groups, the pair of short-circuit tabs disposed in the branched bus bars can be conduction connected with each other by an external wire or by a short-circuit terminal, whereby the branched bus bars can be short-circuited.
According to the second aspect of the invention, since the number of tabs composed of the branched bus bars and conduction connectable together by the external wire is set equal to the number of tabs in the conventional connector, as a mating-side connector to be connected to the wire connecting portion, the conventional connector as it is can be used.
According to the third aspect of the invention, in the subordinate bus bar groups, a plurality of bus bars are held together by a holder. Therefore, when compared with a structure in which bus bars are not held by a holder, the structure according to the invention is improved in the handling efficiency.